An image forming apparatus in which the toner image is formed on a recording material (sheet) and the recording material on which the toner image is formed is heated and pressed by a fixing device (image heating apparatus) and an image is fixed on the recording material has been widely used. In such a fixing device, at a nip formed by a pair of rotatable members, a fixing process is carried out.
In the case in which the recording material is thin and low in rigidity, the recording material is not readily separated from the rotatable members. For this reason, a proposal that an air nozzle is provided in the neighborhood of the rotatable members and the recording material is forcedly separated from the rotatable members by blowing air, supplied from a compressor, from the air nozzle onto the recording material has been made (Japanese Laid-Open Patent Application SHO 60-247672, Japanese Laid-Open Patent Application 2007-94327).
In an air supplying path from the compressor to the air nozzle, many air tubes are provided for being connected between devices. These air tubes are fixed by clamps in a state in which the air tubes are inserted into the devices, and during operation, are constituted so as not be unclamped when the air tubes are in a normal condition.
On the other hand, in the case in which a pressure in the air supplying path is excessively increased by breakage of the device, there is a liability that the air tube is unclamped against a clamp fastening force.
In such a case, a recovery operation is to be carried out, but when all of the portions, in which many air tubes are connected, are checked thoroughly, the recovery operation requires a long time.